Thin film adhesive labels and methods of making thereof

ABSTRACT

Thin film labels, systems, and methods of making and using thereof are described. The thin film systems contain a label and a carrier film, where the label contains an overprint layer, indicia, and an adhesive layer. The carrier film may be coated on one or both sides with a release liner. The adhesive layer can be any suitable adhesive, such as a pressure sensitive adhesive, a fluid activatable adhesive, a heat activated adhesive, or a contact activated adhesive. The label is formed by printed or coating one or more layers of precursor material on the carrier film using standard printers. Suitable precursor materials include, but are not limited to epoxys, solvent cast films, polyurethane dispersions, such as acrylic-urethane hybrid polymer dispersions and polyester-polyurethane dispersions. After the overprint layer dries or is cured, the indicia are printed onto the overprint layer, then the adhesive is coated on top of the indicia.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit of and priority to U.S. Ser. No.62/160,190 filed on May 12, 2015, the disclosure of which isincorporated herein in its entirety.

FIELD OF THE INVENTION

The invention is generally directed to thin film labels and methods ofmaking thereof.

BACKGROUND OF THE INVENTION

Typical container decorations include the use of pressure-sensitivelabels. A typical pressure-sensitive label includes a printed clearfilm, a pressure sensitive adhesive, and a release liner. The label(i.e., the film and indicia) typically adheres to a container with thepressure-sensitive adhesive. The release liner is discarded afterlabeling the containers.

An unprinted laminate construction is typically produced through alamination process where a release liner is laminated to the unprintedclear film using a pressure sensitive adhesive.

Clear film pressure sensitive laminate constructions are popular as theyprovide container decorations with minimal aesthetic interruption causedby labeling media. This allows for a greater focus on the indicia andthe contents of the container.

To reduce material consumption and cost of labeling, it is common to usethin films for both the liner and the label base stock. For example,typical liners are as thin as 0.96-1.2 mils; and typical labels are 1.2mils-3.5 mils in thickness. The liner and label base are typicallyextruded plastics. Typically, there are additional coatings ortreatments present on the label base to enhance printability as well aspromote or allow adhesion of a pressure sensitive adhesive. Typically, aliner base material is coated, siliconized, or treated to allow adequaterelease of a pressure sensitive adhesive during label application.However, thinner films present challenges to the laminating, printing,and application process, as the thin films do not have good handlingproperties. In addition, extrusion processes utilized to make thin filmsalso have diminishing handling properties and efficiencies as filmthickness decreases.

Therefore there is a need for improved thin film labels and thin filmlabeling system, which can be more easily handled.

There is a further need for improved thin film labels and thin filmlabeling systems that do not rely on costly lamination processes.

There is also a need for an improved method for making thin films andthin film labeling systems.

SUMMARY OF THE INVENTION

Thin film labels, systems, and methods of making and using thereof aredescribed. The thin film systems contain a label and a carrier film,where the label contains an overprint layer, indicia, and an adhesivelayer. The carrier film may be coated or treated on one or both sides topromote adhesive layer and/or film release. The adhesive layer can beany suitable adhesive, such as a pressure sensitive adhesive, a fluidactivatable adhesive, a heat activated adhesive, or a contact activatedadhesive.

The films are so thin that they are difficult to handle. Therefore, theyare formed by printing or coating the precursor materials on a supportsubstrate, typically a carrier film.

The label is formed by printing or coating one or more layers ofprecursor material directly on the carrier film using standard printingtechniques. Suitable precursor materials include, but are not limited toepoxys, solvent cast films, polyurethane dispersions, such asacrylic-urethane hybrid polymer dispersions and polyester-polyurethanedispersions. After the overprint layer dries or is cured, the indiciaare printed onto the overprint layer, then the adhesive is coated orapplied by a printing press on top of the indicia.

Since the label is formed using a printer, it can easily be modified toaccommodate different uses.

A plurality of labels is typically formed on a single sheet or web ofcarrier film, which can be rolled. Each label can then be removed andthe adhesive side activated if needed and placed in contact with acontainer. The carrier film is separated from the film label and can bereused and/or recycled when the label is placed on a container.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A and 1B are schematics of a cross-sectional view of a labelsystem prior to placement of the label on a container. The releaselayers and carrier film are attached to the label. In FIG. 1A, releaselayers are present on and abut both sides of the carrier film. In FIG.1B a release layer is present on and abuts only one side of the carrierfilm.

FIGS. 2A and 2B are two schematics of a cross-sectional view of a labelfollowing application of the label on a container. The release layersand carrier film are separate from the label, which is attached to thecontainer. FIG. 2A shows the label system of FIG. 1A in which the labelhas been dislodged from the release layers and carrier film, andattached to a container. FIG. 2B shows the label system of FIG. 1B inwhich the label has been dislodged from the release layer and carrierfilm, and attached to a container.

FIG. 3 illustrates a schematic view of an exemplary manufacturingprocess utilizing a generally continuous web.

FIGS. 4A-4D show four thin film label systems with the same completeindicia, but different areas for the overprint and adhesive layers. Thegray areas represent the overprint and adhesive layers, while the blackareas represent the indicia. FIG. 4A shows a thin film label system inwhich the overprint and adhesive layers are formed from a single labelwhich is rectangular in shape. FIG. 4B shows a thin film label system inwhich the overprint and adhesive layers are formed from a single labelwhich is shaped to be present only where indicia are located. In FIGS.4A and 4B, a single label contains the complete indicia. FIGS. 4C and 4Dshow thin film label systems formed from a group of three and seven thinfilm labels, respectively. Each thin film label in a group contains anoverprint layer, an adhesive layer, and a portion of the completeindicia for the label system.

DETAILED DESCRIPTION OF THE INVENTION I. Definitions

As used herein the term “thin film label system” refers to a thin filmlabel and its carrier material, including any release liners. When inthe form of a system, the carrier material is typically referred to asthe “carrier film”.

As used herein the term “overprint layer” refers to a layer of materialin the thin film label, which covers the indicia when the label isapplied to a container. The overprint layer is generally the outermostlayer of a thin film label, when the label is applied to a container.

As used herein the term “pressure sensitive adhesives” refers to contactadhesives, which in their dry state at room temperature adhere to amultitude of surfaces after being lightly pressed against them.

As used herein the term “UV cured pressure sensitive coating” refers toa pressure sensitive adhesive, which upon exposure to high-intensityultra-violet (UV) light results in an adhesive bond with hightemperature stability and solvent resistance.

As used herein the term “heat activated/thermosetting adhesive” refersto a thermoplastic adhesive which is activated by heat.

As used herein the term “contact activated adhesive” refers to apressure sensitive adhesive that requires light hand pressure to adhereto a multitude of surfaces.

As used herein the term “two-part thermoset adhesive” refers to atwo-component system, which forms crosslinked polymeric resins that arecured using heat and/or heat and pressure for high strength and chemicalresistance.

The terms “styrene acrylic” and “acrylic styrene” as they relate tocopolymers, are used interchangeably herein to refer to copolymershaving the general structure shown below:

wherein x and y are independently integers from 1 to 1000, eachoccurrence of R′ is independently hydrogen, substituted or unsubstitutedalkyl, or substituted or unsubstituted aryl, and each occurrence of R isindependently hydrogen, substituted or unsubstituted alkyl, orsubstituted or unsubstituted aryl. The copolymer can be random, block,branched, or combinations of these. Examples of copolymers of styreneacrylic include, but are not limited to, poly(styrene-co-alkylmethacrylate), such as poly(styrene-co-methyl methacrylate),poly(styrene-co-alkyl acrylate), such as poly(styrene-co-methylacrylate), poly(styrene-co-methacrylic acid), andpoly(styrene-co-acrylic acid)).

The term “elongation to break” refers to ratio of the changed length toinitial length when a sample breaks. Elongation to break can be measuredusing the ASTM D882 standard method.

II. Thin Film Label System

The labels described herein are thin film labels, which have thicknessesof approximately 0.1 mil to 1.5 mil, preferably the thickness of thelabel ranges from 0.4 to 0.6 mil. The thin film labels are typicallyprovided in the form of a roll, where the label is attached to a carriermaterial. Typically the carrier material is coated on both sides with afirst release layer and a second release layer, which allow for therelease of the label from the carrier film, when desired.

Exemplary thin film label systems, which include the carrier film, areillustrated in FIGS. 1A and 1B. As shown in FIG. 1A, the label system100 contains an adhesive coating layer 110, an indicia layer 120, anoverprint layer 130, a first release layer 160, a carrier film 150, anda second release layer 140. The label system can be applied to acontainer 300, and the first release layer 160, carrier film 150, andsecond release layer 140 can be removed. In some embodiments, the secondrelease layer 140 is absent. For example, as shown in FIG. 1B, the labelsystem 100′ contains an adhesive coating layer 110, an indicia layer120, an overprint layer 130, a release layer 160, and a carrier film150. The label system can be applied to a container 300, and then therelease layer 160 and carrier film 150 can be removed from the label.

As shown in FIGS. 2A and 2B, the labels 200 and 200′ that are eachattached to a container 300 contains the adhesive coating layer 110, theindicia layer 120, and the overprint layer 130, where the outer surfaceof the container is directly in contact with the adhesive coating layer110, and the overprint layer 130 is exposed. In FIG. 2A, the label 200has been dislodged from the second release layer 140 and attached to acontainer 300. In FIG. 2B, the label 200′ has been dislodged from thecarrier film 150, and attached to a container 300.

1. Thin Film Label

a. Overprint Layer

Referring to FIGS. 2A and 2B, the overprint layer 130 is generally theoutermost layer of the thin film label 200 or 200′, when the label isattached to a container 300.

i. Coating Materials for Forming Overprint Layer

Coating materials suitable for forming the overprint layer include, butare not limited to, a solventless UV-cured system, water-based orsolvent-based systems such as solution polymers or copolymers, one-partpolyurethane system, two-part polyurethane system (applied at multipleprint or coating stations), hot-melt polymers or copolymers and epoxysystems that can be cured applied at one or multiple print or coatingstations.

Hybrid systems combining the aforementioned are also suitable. Furthersuitable materials include Bayhydrol® UH 240 that is commerciallyavailable from Bayer AG as an anionic polyester polyurethane dispersion,Hybridur 570® that is commercially available from Air Products andChemicals, Inc., as an acrylic-urethane hybrid polymer dispersion,polyurethane dispersions (PUDs), polyethylene (PE) emulsions that areavailable as nonionic, cationic, or anionic emulsions, acrylic and/oracrylic hybrid emulsion systems, and solvent cast film polymersincluding, but not limited to, cellulose nitrate, cellulose diacetate,cellulose triacetate, polycarbonates, polyethersulfone, polyetherimide,polyvinylidene fluoride, polyvinyl chloride (PVC), polyimides, polyvinylalcohol (PVA), methyl cellulose, starch derivatives, gelatin,poly(lactic-co-glycolic acid), copolymers, mixtures of polymers, andcombinations thereof. In a preferred embodiment, the coating materialfor forming the overprint layer is Hybridur 570® or Hybridur 580®.

ii. Properties of Coating

The coating includes polymers that can be in the form of an emulsion,solution, liquid, or solventless formulation. The coating solution,liquid or emulsion can be aqueous or solvent-based. The coating may beformed from two or more precursor solutions, or from a single precursorsolution. Each of the precursor solutions can be sprayed or printed ontothe carrier film and allowed to mix to form the coating.

The preferred viscosity range of the overprint coating is 0 to 1500 cpsat 25° C., most preferred is 25 to 250 cps at 25° C. The preferred pHrange is 6 to 10. Preferred percent solids content is 30 to 60% solidsby weight.

iii. Properties of Dried/Cured Film that Forms the Overprint Layer

Referring to FIG. 1, the dried/cured film forms a continuous, thinoverprint layer 130 that is capable of receiving an ink/dye/pigmentformulation, possesses good tactile feel and flexibility. The overprintlayer 130 can be larger than the indicia, the same size as the indicia,or formulated to be part of the indicia.

This can be accomplished by coating, printing, or casting material ontothe carrier film by using a coating unit or a print station on aprinting press. The overprint layer can also act as a protective barrierto the indicia to increase durability. The overprint layer also providesresistance to moisture, abrasion or scratch, corrosion by chemicals, andstains.

The overprint layer 130 typically has a low percent haze as measured byASTM-D1003 and an excellent elongation to break. Preferably theoverprint layer has a haze measurement ranging from 0% to 20%, mostpreferably ranging from 0% to 10%, as determined using a haze meter,such as the “haze-gloss” instrument available from BYK-Gardner.

Excellent elongation to break can be about 50% or greater, about 75% orgreater, about 100% or greater, about 125% or greater, about 150% orgreater, about 175% or greater, or about 200% or greater as measured byASTM D882 standard method. Preferably the overprint layer has anelongation to break of 200% or greater.

The overprint coating preferably has good wet-out onto the releasecarrier substrate and has medium adhesion to the surface of the releaseliner. For good wet out, the surface energy of the overprint coatingclosely matches the surface energy of the surface to be coated. Forexample, when coating polyester films with a surface energy of 42dyne/cm, the preferred surface energy range of the overprint coating is40-45 dynes/cm. Surface energy can be measured experimentally viacontact angle measurements with a goniometer and tensiometer (such asavailable from Ramé-Hart). Good wet out can also be visually determined.Coatings with good wet out form a consistent film free of voids, ridges,and other visual distractions. Poor wet out is characterized byinconsistent film forming, showing orange peel effects, voids, patterns,ridges, beading or other visually distracting effects.

Medium adhesion of the overprint to the release liner can be measured bythe force required to separate the two layers. The “separation” forcecan be measured by ASTM method D-3330. The preferred force range toachieve medium adhesion is 100 to 1000 g/in. The most preferred range is200 to 600 g/in. The adhesion forces between the adhesive layer and thesurface of the container must be greater than the adhesion forcesbetween the overprint layer and the carrier; however, the adhesionforces between the overprint layer and the carrier must be greater thanthe adhesion forces between the adhesive layer the backside of thecarrier. This allows the system to be self-wound without causingpremature blocking or delamination of the thin label, while stillallowing the thin label to be transferred from the carrier to thecontainer during the application process.

The overprint layer releases cleanly from the release liner. “Releasescleanly”, as used herein, generally means that the overprint layerdelaminates evenly and without defect from the liner and is free ofdebris and buildup as evaluated by visual inspection. Further the lineris smooth and undisturbed as evaluated by visual inspection.

In some embodiments a further coating is placed on top of the overprintlayer. Suitable materials for coating the overprint layer 130 include,but are not limited to, low molecular weight PVC plasticized withPalamoll® 652 and cast from tetrahydrofuran (THF), waterbasedpolyurethane systems (optionally diluted with PVA or other water basedsystems to get better release from film), materials in the Hybridur®Series 878 (N-methyl-2-pyrrolidone (NMP)-free aliphatic urethane-acrylichybrid polymer dispersion), 570 (an acrylic-urethane hybrid polymerdispersion), 870 (NMP-free anionically stabilized acrylic urethanehybrid polymer dispersion), 580 (an acrylic-urethane hybrid polymerdispersion), Sancure® 20041 (alphatic polyurethane dispersion),Impranil® DL 1537 (anionic aliphatic polyester-polyurethane dispersion),Carboset® 514H (acrylic colloidal dispersion polymer in ammonia water),Neocryl® A-1120 (solvent free, high solids, modified acrylic styrenecopolymer dispersion), Joncryl® 544 from BASF (self-crosslinking acrylicemulsion), Dur-O-Set® E-351 (vinylacetate ethylene copolymer emulsion),and combinations thereof.

b. Indicia Layer

The indicia layer 120 is formed from an ink/dye/pigment formulation thatis applied to the overprint layer 130. The ink/dye/pigment formulationincludes carrier solvents and materials dissolved in the solvents. Theink/dye/pigment formulation can be applied and dried onto the overprintlayer 130 or diffuse into the overprint layer 130. The ink/dye/pigmentformulation can be added after the overprint layer 130 is dried/cured orwhile the overprint layer 130 is drying/curing.

The indicia layer can be formed with a number of techniques common tothe art of offset sheet and web based printing. This includes, but isnot limited to, flexographic printing, offset printing, digitalprinting, laser printing, inkjet printing, heat-set printing, gravureprinting, and screen printing. Each technique provides a plurality ofdifferent ink/dye/pigment options that are compatible with this systemand typical for to the art of label printing.

i. Materials

Suitable materials that can be dissolved in the carrier solventsinclude, but are not limited to, a resin, a surfactant and a colorant.

a. Solvent

Generally, the solvent can be any material that can dissolve and/ordisperse the resin and other materials in the ink/dye/pigmentformulation. Depending on the choice of a substrate for which anink/dye/pigment formulation is targeted, a solvent (such as an organicsolvent) can be selected based on the evaporation rate of a solvent.Certain non-aqueous inks have been disclosed in U.S. Patent ApplicationPublication Nos. US 2005/0039634 to Hermansky, US 2009/0246377 toRobertson, et al., and US 2010/0098860 to Robertson, et al. and inpublished PCT applications WO 2010/042104 to Barreto, et al. and WO2010/042105 to Barreto, the entire contents of which are incorporatedherein by reference.

The evaporation rate of a solvent can typically be determined b the ASTMmethod D3359, and can be reported as a relative evaporation rate (RER),usually relative to n-butyl acetate. Based on this RER, the solvents canbe grouped in a manner depending on the application envisioned. Thesolvents are categorized as a fast, intermediate and a slow solventaccording to their RERs: solvents having a RER greater than 1.0 can begrouped as fast solvents; solvents having a RER from about 1.0 to about0.01 can be grouped as intermediate solvents; and solvents having a RERless than about 0.01 can be grouped as slow solvents. The RERs cantypically be correlated with the volatility of a solvent. A fast solventtypically evaporates faster and can lead to rapidly increasing viscosityof an ink. Although a solvent may be mentioned as a single chemicalentity, derivatives of such solvents can include its structural isomersand other oligomers. The organic solvents described herein, may be usedeither in an anhydrous or wet form.

Examples of fast solvents can include methanol, ethanol, propanol,iso-propanol, acetone, methyl ethyl ketone, methyl isobutyl ketone,pentane, hexane, heptane, methyl acetate, ethyl acetate, propyl acetate,tert-butyl acetate, tert-butanol, tetrahydrofuran, and their mixtures.

Examples of intermediate solvents can include C₄₋₈ alcohols (e.g.,butanol, pentanol, hexanol, heptanol, octanol, and the like), propyleneglycol ethers (e.g., propylene glycol mono methyl ether, propyleneglycol mono ethyl ether, propylene glycol n-propyl ether, propyleneglycol n-butyl ether, and the like), dihydric alcohols (e.g., ethyleneglycol, propylene glycol, butylene glycol, and the like),1-methoxy-2-acetoxy propane, cyclohexanone, and their mixtures.

Examples of slow solvents can include, but are not limited to, glycolethers having at least about 10 carbon atoms (e.g., at least about 11carbon atoms, at least about 12 carbon atoms, at least about 13 carbonatoms, at least about 14 carbon atoms, or at least about 15 carbonatoms), dipropylene glycol methyl ether, dipropylene glycol methyl etheracetate, dipropylene glycol n-butyl ether, tripropylene glycolmonomethyl ether, tripropylene glycol-n-butyl ether, propylene glycolphenyl ether, and their mixtures. The RERs of certain glycol ethers havebeen reviewed by Smith, R. L., in Environmental Health Perspectives,Vol. 57, pp, 1-4 (1984), the entire disclosure of which is incorporatedherein by reference. Examples of commercial solvents include “DowanolTPM tripropylene glycol methyl ether,” and “Dowanol PM propylene glycolmethyl ether” available from Dow Chemical (Midland, Mich.).

The approach described above, using different types of solvent, is wellsuited to develop conventional printing inks. Also contemplated arematerials and approaches employed to develop other types of printinginks, such as toner inks for a laser printer. For example, U.S. Pat. No.8,206,884 to Yang, et al., describes a method for preparing toner usingmicro-suspension particles, the entire contents of which areincorporated herein by reference.

b. Resin

The resin typically provides the ink/dye/pigment formulation with adesired viscosity, thermal stability, flexibility, and adhesionproperties. Examples of resins include, but are not limited to, rosinmodified phenolic resins, phenolic resins, styrene-acrylic resins,polyketone resins, derivatives thereof, or mixtures thereof. The inksoptionally include other types of resins, such as polyvinyl butyral(PVB), acrylic, polyurethane, polyamide, polyvinylpyrrolidone (PVP), orvinyl resins, acacia (gum arabic); gum ghatti; guar gum; locust (carob)bean gum; karaya gum (sterculia gum); gum tragacanth; chicle; highlystabilized rosin ester; tall oil; manila copais; corn gluten;coumarone-indene resins; crown gum; damar gum; p, alpha-dimethylstyrene; gum elemi; a rosin glycerol ester; an ethylene vinyl acetate(EVA); a polyamide resin; ethylene oxide polymer and its adducts;ethylene oxide/propylene oxide copolymer and its adducts; galbanumresin; gellan gum; ghatti gum; gluten gum; gualac gum; guarana gum;heptyl paraben; cellulose resins, including methyl and hydroxypropyl;hydroxypropyl methylcellulose resins; isobutylene-isoprene copolymer;mastic gum; oat gum; opopanax gum; polyacrylamide; modifiedpolyacrylamide resin; polylimonene; polyisobutylene (min. MW 37,000);polymaleic acid; polyoxyethylene derivatives; polypropylene glycol (MW1200-3000); polyvinyl acetate; polyvinyl alcohol; polyvinylpolypyrrolidone; polyvinyl pyrrolidone; rosin, adduct with fumaric acid,pentaerythritol ester; rosin, gum, glycerol ester; rosin, gum or wood,pentaerythritol ester; rosin, gum or wood, partially hydrogenated,glycerol ester; rosin, gum or wood, partially hydrogenated,pentaerythritol ester; rosin, methyl ester, partially hydrogenated;rosin, partially dimerized, glycerol ester; rosin, partiallyhydrogenated; rosin and rosin derivatives; rosin, polymerized, glycerolester; rosin, tall oil, glycerol ester; rosin, wood; rosin, wood,glycerol ester; purified shellac; styrene; styrene terpolymers; styrenecopolymers; sucrose acetate isobutyrate; terpene resins, natural andsynthetic; turpentine gum: vinylacetate; vinyl chloride-vinylidenechloride copolymer; zanthan gum; and zein.

Examples of commercial resins include the Joncryl family of resins(available from BASF), Reactol K3107 (a phenolic resin from Hexion),Resin SK (a polyketone resin from Evonik), Alnovol PN320 novolakphenolic resin from Cytec), Laropal A81 (an aliphatic aldehyde resinfrom BASF), and ‘Fora’ 85 hydrogenated rosin ester resin, available fromHercules Chemical Company, Inc.; 111 South Street, Passaic, N.J. 07055.Preferred molecular weights for these polymers range from 150,000daltons to 1,000,000 daltons, more preferably from 200,000 daltons to500,000 daltons.

c. Surfactant

Optionally, the ink/dye/pigment formulation includes one or moresurfactants. The surfactant(s) can serve to alter the surface tension ofthe ink/dye/pigment formulation. Suitable types of surfactants include,but are not limited to, anionic (such as sulfate esters, carhoxylates,sulfonates, or phosphonates), cationic, nonionic (such as polyol based,polyglycerols based, fluorocarbon based, siloxane-based, alkyl phenolbased, or polyoxyethylene based) or amphoteric (such as phosphatides,imidazoline derivatives, or betaines) surfactant compounds, such asthose described in “Surfactants and Interfacial Phenomena,” SecondEdition; M. J. Rosen; 1989, John Wiley and Sons, Inc., New York, pages1-32, the contents of which are incorporated herein by reference.

The inclusion of a surfactant within an ink/dye/pigment formulation canlead to a barrier in the form of a layer of surfactant at the interfaceof air and bulk ink, thereby reducing, and preferably substantiallyeliminating, the ability of the solvent to evaporate from the bulkink/dye/pigment formulation. By reducing the solvent evaporation rate,and preferably entirely preventing solvent evaporation of theink/dye/pigment formulations, the decap time can be increased. At thesame time, once an ink/dye/pigment formulation is placed onto asubstrate, fast evaporation (i.e., fast drying time) can occur becausethe surfactant molecules can spread out over a larger surface areainstead of being confined to a surface that is under tension.

Fluorosurfactants are surfactants that can either be ionic (with thefluorine-containing moiety being part of either the cationic or theanionic part) or nonionic (such as fluorocarbon chain-containingalcohols). The fluorosurfactants can be ethoxylated surfactants (i.e.,polyethyleneoxide modified) or polytetrafluoroalkylene surfactants.Ethoxylated surfactants include one or more of ethylene oxide monomericunits. Polytetrafluoroalkylene surfactants include one or more oftetrafluoroalkylene units. Examples of fluorosurfactants includepolyethylene oxide-b-poly(tetrafluoroethylene) polymers,2-(perfluoroalkyl)ethyl stearate, anionic lithium carboxylatefluorosurfactant, anionic phosphate fluorosurfactant, anionic phosphatesurfactant, amphoteric quaternary ammonium-acetate fluorosurfactant,fluoroaliphatic polymeric esters, their derivatives, and their mixtures.Examples of commercial fluorosurfactants include Zonyl family offluorosurfactants (e.g., Zonyl FSO 100, Zonyl FSN, Zonyl FTS) andCapstone family of fluorosurfactants (available from DuPont Chemicals,Wilmington, Del.), or Fluorad FC 170-C, FC171, FC430 and FC431 availablefrom 3M of St. Paul, Minn. Hermansky (see above) discloses the completedrying of the inks in the presence of Zonyl FSX surfactant.

Siloxane-based surfactants are surfactants which can be copolymers ofsilyl ethers and epoxy (ethylene oxide, propylene oxide) oligomers orpolymers. Examples of siloxane-based surfactants includepolysiloxane-b-ethylene oxide, polysiloxane-b-propylene oxide,polysiloxane-b-propylene oxide/ethylene oxide, their derivatives, andtheir mixtures. Examples of commercial siloxane-based surfactantsinclude copolymers such as SILWET® copolymers including Silwet L-7604,available from GE Silicones; Troysol Q-148 and 5366 available from TroyChemical.

Acetylenic diol-based surfactants are surfactants which can beacetylenic diols comprising hydrophobic groups at the end of theacetylenic spacer and hydrophilic and/or hydrophobic ethers hanging offof the hydroxyl groups. Examples of acetylenic diol-based surfactantsinclude, 2,4,7,9-tetramethyl-5-decyne-4,7-diol (TMDD),2,5,8,11-tetramethyl-6-dodecyne-5,8-diol, their derivatives, and theirmixtures. Examples of commercial acetylenic diol-based surfactantsinclude Dynol series (Dynol 604) and Surfynol series (Surfynol 104, 420,465, 485, TG-E, SE, etc.) available from Air Products.

Hydrocarbon-based surfactants are surfactants which can bepolyoxyethylenated alkyl phenols (APE type), polyoxyethylenated shortchain alcohols (AE type), or long chain organic acid esters. Examples ofhydrocarbon-based surfactants include polyoxyethylene (10)isooctylcyclohexyl ether, (1,1,3,3-tetramethylbutyl)phenyl-polyethyleneglycol, polyethylene glycol tert-octylphenyl ether,polyoxyethylenesorbitan monopalmitate, their derivatives, and theirmixtures. Examples of commercial hydrocarbon-based surfactants includeTriton X Series and Tergitol Series, both from Dow Chemical; the TWEENSeries from ICI Americas; and the Igepal Series from Hallstar.

d. Colorants

The ink/dye/pigment formulation may include a colorant, which providescolor to the ink/dye/pigment formulation. The ink/dye/pigmentformulation can contain a sufficient amount of a colorant that theink/dye/pigment formulation has color, but not so much as to interferewith other desirable qualities, such as surface tension or viscosity.

An ink/dye/pigment formulation can include one or more colorants (e.g.,one or more pigments, one or more dyes, or their mixtures). Colorantscan provide an ink/dye/pigment formulation with, for example, a desiredcolor and/or opacity. Exemplary colors can include black, cyan, magenta,yellow, red, blue, green, brown, or their combinations.

Examples of suitable pigments include Color Index Pigment Black 7;Pigment Blue 15; Pigment Red 112, 146, 170 and 208; Pigment Yellow 17and 83; Pigment Green 7; carbon black, graphite; and pigment whitetitanium dioxide. Additional examples are disclosed in, e.g., U.S. Pat.No. 5,389,133 to Xerox Corporation, the entire contents of which areincorporated herein by reference. The pigment may also have a modifyinggroup on its surface, such as an oxygen-containing functionality (e.g.,a carboxyl or phenol group). An example of a commercially availablepigmented colorant can be “Special Black 4A” available from EvonikDegussa (Germany).

Examples of dyes include Orasol Pink 5BLG, Black RLI, Blue 2GLN, Red G,Yellow 2GLN, Blue GN, Blue BLN, Black CN, and Brown CR (all availablefrom Ciba-Geigy, Inc., Mississauga, Ontario); Morfast Blue 100, Red 101,Red 104, Yellow 102, Black 101, and Black 108 (all available from MortonChemical Company, Ajax, Ontario); and a mixture thereof.

e. Other Modifying Agents in the Ink/Dye/Pigment Formulations

The ink/dye/pigment formulations can contain smaller amounts of otheringredients without hindering the desired properties of the inks. Suchingredients include, but are not limited to, dispersants, anti-foamingagents, wetting agents, viscosity modifiers, and light stabilizers.

ii. Properties

The indicia layer 120 provides decoration to the substrate, informationabout the contents of the labeled container, or both. In someembodiments, the indicia layer in a single label provides the completeindicia, i.e. the desired decoration to the substrate, information aboutthe contents of the labeled container, or both. In this instance, theoverprint layer 130, the adhesive layer 110, or both, each form acontinuous layer upon or under which the indicia layer 120 is located.Preferably, both the overprint layer 130 and the adhesive layer 110 formcontinuous layers. See, FIGS. 4A and 4B.

In other embodiments, the information and/or design on a group of labelswhen assembled together provides the complete indicia. See, e.g. FIGS.4C and 4D. In these embodiments, each indicia layer in each of thelabels in the group 30 provides a portion of the indicia in the completeindicia. The complete indicia is located on and/or under discontinuousregions that contain an adhesive layer upon which a portion of thecomplete indicia is located. When assembled together on a substrate, thegroup of labels define regions on the substrate where a label islocated, and each label is separated from another label by a region ofthe substrate that does not contain a label (or an adhesive layer, oroverprint layer, or both).

The addition of surfactants to the ink/dye/pigment formulation used toproduce the indicia layer 120 can provide an extended decap time withoutcompromising the drying time on a substrate. Surfactants can also alterthe viscosity of the formulations and can further prevent the viscosityof the formulations from altering.

Viscosity ranges of the inks are very wide and depend on printingmethod. Offset printing inks typically range in viscosity from 40,000 to100,000 cps at 25° C. Gravure and flexographic printing inks typicallyrange in viscosity from 50 to 500 cps at 25° C.

c. Adhesive Layer

Referring to FIG. 2, the adhesive layer 110 covers the indicia layer,and forms the innermost layer of the label system when the label is incontact with a substrate, such as a container 300. The adhesive layer110 provides sufficient adhesive force to attach the label to thedesired container substrate. This includes enough force to delaminate ortransfer the overprint layer and indicia layer from the release carrierto the container and maintain enough force to secure the label to thecontainer. The type and strength of the adhesive layer determines thetype of release coating or treatment on the carrier film.

Optionally, a layer can exist between the indicia layer and the adhesivelayer to provide barrier properties to the indicia from the adhesive orto provide a priming effect for the adhesive.

The adhesive composition used to form the adhesive layer can be apressure sensitive adhesive (PSA), such as a clear water-based pressuresensitive coating, UV cured pressure sensitive coating, heatactivated/thermosetting adhesive, contact activated adhesive, two-partthermoset adhesive and/or fluid activated adhesive. Approaches to applythe adhesive layer to the indicia layer include, but are not limited to,utilizing a printing press or coating station on a printing press.

i. Materials

The adhesive compositions can contain a single polymer (e.g.,homopolymers, copolymer, terpolymer, etc.) or a mixture of polymers,such as homopolymers, copolymers, terpolymers, etc., and combinationsthereof.

a. Pressure Sensitive Adhesives

In some embodiments, the adhesive layer contains a pressure sensitiveadhesive (PSA) and one or more tackifiers. These adhesives may be usedto reduce the contact pressure required to bond the layers together,and/or increase the adhesion between the layers. PSAs include polymerssuch as polyethylenes, polysiloxanes, polyisobutylenes, polyacrylates,polyacrylamides, polyurethanes, plasticized ethylene-vinyl acetatecopolymers, and tacky rubbers such as polyisobutene, polybutadiene,polystyrene-isoprene copolymers, polystyrene-butadiene, neoprene(polychloroprene), copolymers, and mixtures of polymers.

b. Fluid Activatable Adhesive Compositions

In some embodiments, the adhesive layer is a non-tacky fluid activatableadhesive. Exemplary fluid activatable adhesives and their correspondingactivation agents are described in pending application, U.S. Ser. No.14/310,913, filed Jun. 20, 2014, the disclosure of which is incorporatedby reference in its entirety.

ii. Properties

The adhesive layer can be applied to glass and plastics commonly used incommercial applications including, but not limited to, polyethyleneterephthalate (PETE, PET, PETG), polyethylene (PE), polystyrene (PS),low-density polyethylene (LDPE), linear low-density polyethylene(LLDPE), high density polyethylene (HDPE), polypropylene (PP), polyvinylchloride (PVC) and polyvinyl chloride films, and TYVEK®, as well asother low energy and thermoplastic substrates. The adhesive layer canalso be applied to paper, cardboard, or metal surfaces.

The adhesive layer provides good adhesion to the desired substrate. Itis also optically clear. The adhesive layer is preferably formulated forcaustic removability, such that the container and label can be separatedin a recycling plant or bottle washer.

d. Carrier Film

The carrier film provides a base that can support the overprint layerduring the printing and application processes. The starting material forthe carrier film optionally has one or more release coatings alreadyapplied to its surfaces. Optionally, the carrier film is coated on itsupper and/or lower surfaces with release coatings, where the releasecoating on the lower surface allows for easier release of the adhesivelayer compared to the release of the overprint layer from the releasecoating on the upper side of the carrier film.

i. Materials

Suitable materials that can be used to produce the carrier film include,but are not limited to, polyethylene terephthalate (PET), polyethylene(PE), polypropylene (PP), polystyrene (PS), polyesters, polyamides,polyvinyl chloride, co-polymers such as styrene/acrylonitrilecopolymers, ethylene/propylene copolymers, styrene/acrylonitrilecopolymers, ethylene/butene-1, copolymers, ethylene/ethyl acrylatecopolymers, ethylene/methyl methacrylate copolymers, ethylene/vinylacetate copolymers.

ii. Properties

The carrier film is preferably flexible, low cost and strong. Carrierfilms are available with a variety of coatings/treatment to allow forthe proper release of the adhesive layer when the label construction iswound or rolled such that the adhesive layer is in contact with thecarrier film.

iii. Release Coatings on One or Both Sides of the Carrier Film

Referring to FIG. 1A, a first release layer 160 and a second releaselayer 140 are applied to opposite sides of the carrier film 150. If theadhesive is a PSA, the second release layer 140 prevents the adhesivecoating layer 110 from strongly adhering to the carrier film 150.

Referring to FIG. 1B, a second release layer 140 is not applied to thecarrier film 150 (i.e. only one release layer is present). In thisembodiment, the surface of the carrier film has inherent releaseproperties. Optionally the material that forms the carrier film 150 isPET, PP, or PS.

Referring to FIG. 2A, after the label system is applied to a container300 via the adhesive coating layer 110 the first release layer 140facilitates the detachment of the carrier film 150 from the label 200.In FIG. 2B, the second release layer 140 is not present. The overprintlayer 130 becomes the outermost layer of the label 200. The firstrelease layer and second release layer may not, and often do not, havethe same levels of release. In some embodiments, the first release layerand second release layer are formed from the same materials, but withdifferent percent compositions or viscosities. In other embodiments, thefirst release layer and second release layer are formed from differentmaterials.

e. Release Layers

i. Materials

Suitable materials that can be used to produce the release layersinclude, but are not limited to, silicone, high density polyethylene(PE), medium density PE, low density PE, polypropylene (PP),polytetrafluoroethylene (PTFE), acrylated silicone, polyesters, PET,polyethylene naphthylene, polyamides, co-polymers and mixtures thereof.

ii. Properties of Release Coatings

a. First Release Layer

Referring to FIG. 2A, the first release layer 160 can be formulated toresist blocking with the adhesive layer 110 when the label system iswound, rolled or stacked, resist moisture, or both, i.e., resistblocking and moisture.

b. Second Release Layer

Referring to FIG. 2A, the second release layer 140 can be formulatedsuch that there is no hazing on the overprint layer 130 after the label200 is transferred to a substrate, such as a container 300. In someembodiments, in which the surface of the carrier film has inherentrelease properties, the second release layer 140 is absent (see, e.g.FIG. 2B).

III. Methods of Making Thin Film Labels with Indicia

The starting materials for forming the thin film labels described hereinare a carrier film with or without release characteristics alreadyapplied to it. The label is built from a coating that becomes theoverprint layer using standard coating and/or printing presses andtechniques. This allows for a very small amount of material (relative toan extruded film) to be utilized. As this material is coated or printeddirectly onto the carrier film, its low caliper does not create thehandling challenges typically associated with thin film extrusion andlamination.

The method for forming the thin film labels uses standard printers tobuild a label using coatings and inks typical to the industry, bypassingexpensive lamination processes.

An exemplary manufacturing process for forming the thin film labels withindicia is depicted in FIG. 3.

A schematic view of an example manufacturing process 5000 of the varioussteps associated with forming the thin film labels described herein isillustrated utilizing a generally continuous web 5004. A carrier film150 can be provided as a generally continuous web that can be processedthrough a “reel-to-reel” style manufacturing process.

For example, the carrier film can be provided as a generally continuousweb 5004 from a source station 5002, which can be a source roll or thelike. Some or all of the various processing steps, such as, for example,the steps of coating a material onto the carrier film to form theoverprint layer, can then be performed by passing the generallycontinuous web 5004 through a printing station 5008. Though only asingle printing station 5008 is illustrated. However, it is to beunderstood that multiple printing stations can be utilized. In additionor alternatively, though not illustrated, the process 5000 can beadapted to pass the web 5004 through the printing station 5008 inmultiple passes. For example, the indicia can be print on top of theoverprint layer by passing the web through the printing station one ormore times. Finally, the completed plurality of label systems on thegenerally continuous web 5004 can be collected at a take-up station5010, which can include a collection roll to form a rolled label system,as well as finishing equipment, including die-cutting and matrixstripping equipment.

The manufacturing process 5000 can include various other stages, steps,etc. For example, pre-processing and/or post-processing stations, steps,etc. can also be included. It is to be understood that the additionalequipment may be provided (e.g., idler rollers, tension rollers,turn-bars, slit or perforators, etc.) to facilitate the “reel-to-reel”process.

1. Coat or Print Coating Material onto Carrier Film

Any suitable printing technique and system can be used to coat or printthe carrier film with the material for forming the overprint layer.Examples of suitable techniques include web coating technique,including, but not limited to gravure, reverse gravure, slot die, rod,knife-over-roll, flexographic, or offset coating.

For example, a typical flexographic or gravure printing press may beused to coat a carrier film with one or more layers of pressprintable/coatable coatings.

The carrier film is coated, flood printed, or spot printed with asufficient amount of a polymeric material to form an overprint layer.This is preferably accomplished at a single print or coating station,but can take place across one or more stations. Alternatively, theoverprint layer may be prepared prior to the printing process in awide-web or larger format construction. Coating or printing the layerdirectly on the carrier allows for the label to be built on the carrierweb on the coating or printing equipment. This allows for flexibility inchoosing the thin label material and a reduction in complexity of thesupply chain of label material. It also provides for a reduction in theamount of material required. Typical thin film labels that are madeusing prior art methods may be as thin as 1.2 to 3.5 mils. In contrast,the films described herein are thinner, with typical label thicknessesranging from 0.1 to 1.5 mils.

i. Printing

The thin film labels can also be produced using consumer or commerciallaser printing techniques. Laser print engines are able to depositindicia and coating in registration onto carrier film webs or sheetsusing an electrostatic digital printing process.

Laser printing produces high resolution text, graphics, and coatings byrepeatedly passing a laser beam back and forth over a negatively chargedcylinder or drum to define a differentially-charged indicia or transferregion on the drum. The drum then selectively collects electricallycharged powdered resin and pigment formulations (toner), and transfersthe toner to the web or sheet. The toner and sheet then typically passover a fuser that heats the toner allowing it to melt and form acontinuous or semi-continuous polymeric film, typically containingpigments or dyes.

Toner can generally be described as mono-component magnetic,mono-component non-magnetic, or dual component. Despite these differentcategories, which are based upon the type of development process used inthe laser print engine, all powder toners contain a polymeric resin.Most also contain a colorant and a series of additives having a varietyfunctions.

The polymeric resin is the ingredient of the toner that represents themajor proportion of any toner composition. Depending on the type oftoner composition, the composition of the polymer ranges between 40 and95% by weight of the toner composition. Typically, the function of thepolymer is to act as a binder to carry and hold the colorant on thefinal printed sheet or web. In this example, the toner from a specificprint station or drum can act as a traditional binder or can also act asthe overprint layer. When acting as an overprint layer, the polymers aredeposited onto the web or sheet, and fused, followed by the depositionof additional layers on top of the overprint layer to form the thin filmlabel. The label is initially adhered to the web or sheet, but willeventually be delaminated when the label is transferred from the carrierweb or film onto a desired container or substrate.

Toner formulations that can be used to produce the thin film labelscontain amorphous polymers that have a glass transition temperature (Tg)from about 20° C. to about 80° C., or from about 40° C. to about 70° C.,preferably from about 50° C. to about 70° C.

Exemplary polymers that act as both a binder and an overprint layerinclude: resins formed from copolymers of styrene acrylic,poly(styrene-co-butadiene), polyester resins, HDPE, LDPE, and PP.

In addition to polymers, a toner formulation for a thin film label alsocontains a charge control agent that enables the charge characteristicsof the toner to be fine-tuned, a flow control additive (for examplefumed silica) to prevent the toner from caking, and a wax to prevent thetoner from sticking to the heated fuser rollers.

Polyesters have the advantages of giving the toner a lower minimum fixtemperature, while maintaining a higher Tg. Styrene/acrylic copolymers,such as those described above, have the advantage of possessing a lowerhumidity sensitivity, which translates into a more robust performance ina variety of environmental conditions. As this layer, is the outermostlayer once the label is transferred or applied to a container, humidityresistance for wet environments can be important in order to protectprint fidelity.

Printing coating material onto carrier film also facilitates the designof thin film label systems that have any desired shape including, butnot limited to, oval, square, rectangular, etc. Further, the thin filmlabels are also designed such that the overprint and adhesive layers arepresent only in area where indicia is located. “Adhesive coating layer”and “adhesive layer” are used interchangeably to refer to the layer ofthe thin film labels, which contains the adhesive materials.

a. Label Formed from a Plurality of Labels

Designing the overprint layer 130 and adhesive layer 110 to closelymimic or outline the indicia layer 120 also provides an aesthetic thatis typically not able to be accomplished through the use of currentlyavailable pressure sensitive labels. This aesthetic provides ano-label-look more typical of direct screen printing on containerswithout the material waste associated with die-cutting and matrixstripping pressure sensitive label material.

In these embodiments, the outline of the adhesive layer 110, theoverprint layer 130, or both, may be discontinuous around portions of acomplete indicia. In these embodiments the layouts, also calledoutlines, of the adhesive layer 110 and overprint layer 130 mimic eachother, although this is not always required. A large overprint layerlayout is also used to demonstrate the tactile properties achievablethrough this label construction.

In some embodiments, a carrier film contains a group of two or morelabels that when assembled together define a complete indicia. In theseembodiments, each label in the group is separated from the other labelsin the group. Thus, the outline of one label (and its adhesive layer,optionally its overprint layer, if one is present) in the group isdiscontinuous with the outline of each of the other labels (and theircorresponding adhesive layers, optional overprint layers, if present),creating a plurality of thin film labels that are supported on thecarrier film to maintain spacing and registration. During application toa substrate, such as the surface of a container, this spacing andregistration is typically maintained. The ability to fabricate and applya plurality of labels in registration also provides a unique aestheticnot achievable with conventional pressure sensitive laminate labels.

These embodiments are further described by referring to FIGS. 4A-4D. Ingeneral, FIG. 4A, contains the indicia layer in a single label that hasa single continuous outline of the overprint layer 130 and adhesivelayer 110, which provides a complete indicia, i.e., the desireddecoration to the substrate, information about the contents of thelabeled container, or both are contained in a single continuous outlineof overprint and adhesive layers. As shown in FIG. 4A, the thin filmlabel system 400 a contains print indicia 120 a, 120 b, and 120 c, andan overprint layer 130. The shape 105 of the thin film label isrectangular.

FIG. 4B shows another thin film label system, 400 b that contains printindicia 120 a′, 120 b′, and 120 c′. The overprint layer 130 and adhesivelayer are present only where indicia are located. In FIG. 4B, the samecomplete indicia as shown in FIG. 4A is present, and is contained in asingle label that has a single continuous outline. However, the regionscontaining the overprint and adhesive layers is more closely associatedwith regions containing the indicia compared to FIG. 4A, such that lesssurface area contains the overprint and adhesive layers compared to thesurface area of the overprint and adhesive layers in the label of FIG.4A.

In FIGS. 4C and 4D, the indicia on the label shown in FIG. 4A arepartitioned into three and seven separate labels, respectively, eachcontaining a portion of the indicia shown in the label of FIG. 4A. Forexample, when the three labels shown in FIG. 4C are combined, they formgroup of labels that has a discontinuous outlines of the individuallabels in the group (and discontinuous outlines of their correspondingadhesive and overprint layers), but includes the complete indicia, asshown in FIG. 4A.

FIG. 4C shows a thin film label system 400 c formed from a group oflabels containing three thin film labels, 401 a″, 401 b″, and 401 c″,each containing a portion of indicia 120 a″, 120 b″, and 120 c″,respectively, of the complete indicia. The portions of indiciacollectively form the complete indicia (as shown in FIGS. 4A and 4B).

FIG. 4D shows a thin film label system 400 d formed from a plurality ofseven thin film labels 401 a′″, 401 b′″, 401 c′″, 401 d′″, 401 e′″, 401f″, and 401 g′″, each containing a portion of indicia. Indicia 120 a′″,120 b′″, and 120 c′″ are identified for thin film labels 401 a′″, 401b′″, and 401 c′″. The portions of indicia for all seven thin film labelscollectively form the complete indicia.

These designs of thin label systems are obtained using flexographicprinting and coating. As is typical with flexographic printing andcoating, the flexograhic inking system contains an ink/coating fountainor pan, in which the ink or coating is stored. A fountain roller rotatedin the pan, picking up a film of ink/coating on its rubber-coveredsurface. The fountain roller acts to effectively deliver ink/coating tothe surface of the adjacent anilox roller. The anilox rollers arechrome-plated or ceramic-covered rollers containing pyramid-shaped cellsembedded in its surface. Other shapes that can be used include, but arenot limited to hexagonal-patterns or diamond-shapes. The function of theanilox roller is to deliver a predetermined amount of ink/coating to theadjacent flexographic printing plate. The inks utilized are typical inksutilized for water-based flexographic printing. Examples include, butare not limited to, SolarAqua, SolarClear, SolarFlex, SolarScreen,and/or SunBeam (all manufactured by SunChemical).

2. Dry or Cure Coating Material to Form Overprint Layer

After the polymeric material is coated or printed onto the carrier film,it is dried or allowed to dry or cure. In some embodiments, the coatingmay be air-dried, IR oven dried, forced air oven dried, or cured usingUV, electron beam, or other energy source to form the overprint layer.Typical periods for drying the polymeric material to form the overprintlayer include open air drying, convection air drying, IR oven drying,and UV oven drying and curing. Generally, the press or coater speed andthe oven length will dictate the amount of time the coating is allowedin the oven. In aqueous and solvent-based systems, preferably thecoating is able to dry to below 5% (by weight) moisture while in theoven. For a typical flexographic printing press, speeds of greater than1,200 feet per minute are obtainable with the use of forced air ovenstypical to the industry.

3. Apply Inks to Exposed Surface of Overprint Layer to Form IndiciaLayer

The ink/dye/pigment formulation(s) are typically applied using reversetransfer printing processes. In this process, the printer releases oneor more ink/dye/pigment formulations onto the exposed surface of theoverprint layer. The image that is printed on the surface is oriented asthe mirror-image of the indicia that will be viewable when the label isplaced on the container.

Different ink/dye/pigment formulations can be applied simultaneously orsequentially to obtain indicia with the desired appearance.

4. Apply Adhesive Layer to Exposed Surface of Indicia Layer and ExposedSurface of Overprint Layer, if any

After the indicia are printed on the overprint layer, a suitableadhesive composition is coated or spot printed on top of the indicia,and any exposed portion of the overprint layer.

5. Form Roll of Labels

Once the formation of the label is complete, the label system is cut tothe desired size, scored, if necessary, optionally separation portionsare located between the individual labels in a set of printed labels.Finally, the set of labels is rolled to form a roll of labels.

IV. Methods of Using Thin Film Labels with Indicia

In use, a roll of a plurality of labels may be provided. High speedlabeling systems can be used to remove one label at a time and adherethe adhesive layer to the desired surface of a container. Alternatively,the thin label can be transferred directly from the carrier film to thecontainer by running the carrier film and thin label into direct contactwith the surface of the container.

The carrier film can also be used to drive the label through a series ofrollers to ensure uniform tension as the thin label system is contactedwith the container.

As the adhesive layer adheres the label to the container, the overprintlayer separates from the release layer that is attached to the carrierfilm, allowing the label to attach to the container.

Each successive label is removed, as described above, leaving a longroll of carrier film, which can be rewound and reused to form anotherroll of labels or optionally, recycled or otherwise disposed of.

When the label is placed on a container, the indicia layer is trappedbetween the surface of the container and the overprint layer, whichprotects the printed material.

In some cases the carrier film can be cut using the label applicationequipment or supplied in a precut form and also applied to thecontainer.

The carrier film can optionally also carry indicia. This provides asystem where the container is permanently labeled with a thin-film clearlabel and semi-permanently labeled with a removable carrier film.

The present invention will be further understood by reference to thefollowing non-limiting example.

EXAMPLE Example 1 Thin Film Label Via a Coating Technique

A thin film label was constructed with an untreated PET carrier sheethaving a thickness of 3.0 mils (SG00-300 by SKC Films). The overprintlayer, containing a blend of 95% Hybridur 580 and 5% polyethylene waxdispersion, was coated onto the carrier film using a Mayer rod techniquewith an approximate dry coat weight of 4 grams/square meter. Theoverprint layer was dried in a forced air oven. Indicia were applied tothe overprint layer using an electrostatic digital transfer printing(laser printing) technique. An adhesive layer containing Encor 123 wasthen applied to the web at a coverage of 5 dry grams/square meter usinga Mayer rod technique. The adhesive layer was dried in a forced airoven.

The resulting label had a low percent haze, i.e. excellent clarity.

The thickness of the overprint, indicia, and adhesive layer was 0.5mils.

Example 2 Thin Film Label Via Printing Press Techniques

In another example, the thin film label was prepared utilizing an eightstation flexographic printing press (Table 1). Referring to FIG. 2B, inthis example, the carrier sheet 150 was a one-side-coated PET releaseliner (Silphan S50 produced by Siliconature) where the side of the PETrelease liner being printed upon was untreated. The side of the carriersheet opposite to that having the PET release liner was coated with asilicone coating 160 to enhance release. The press was configured toallow for one to two press stations to be utilized for the printing ofthe overprint coating layer 130; another one to four press stations tobe utilized for the printing of the indicia 120 (Flexographic colors1-4), and another one to two stations to be utilized for the printing ofa pressure sensitive adhesive 110.

TABLE 1 Press stations from an eight station flexographic printingpress, used to prepare thin film labels Press Station Anilox RollerCoating/Ink 1 440 Overprint Coating 2 440 Overprint Coating 3 600Flexographic Color 1 4 800 Flexographic Color 2 5 800 Flexographic Color3 6 800 Flexographic Color 4 7 440 Pressure Sensitive Adhesive 8 160Pressure Sensitive Adhesive

The anilox rollers were chrome-plated or ceramic-covered rollerscontaining pyramid-shaped cells embedded in its surface. Theflexographic printing plates were set using a computer-to-platephotopolymer system. The imprinting of the flexographic printing platedictates where coating and/or ink will be applied on the transfercarrier at the first printing stations and on top of previousprints/coats on all following printing stations. In one example, FIG.4D, this allowed for the overprint layer 130 to only be applied in areaswhere indicia 120 is applied. This greatly minimized the area and volumeof material needed to fabricate a label.

The overprint layer 130 contained between 80% to 100% Bayhydrol® UH 240,0% to 20% ethanol (to control foam and coating cosmetics), and 0% to 1%of Blankophor P150 (Indulor America, Graham, NC)—a stilbene fluorescentwhitening agent. Blankophor P150 is a black light sensitive dye thatprovides visual registration of layers under black light withoutcompromising the optical clarity/haze of the dried coating). The driedlayer possessed excellent clarity, elongation to break, and ultimatetensile strength. The inks utilized were typical inks utilized forwater-based flexographic printing.

The adhesive used was a formulation containing between 95% and 100%Arkema 9466 (from Arkema) and between 0% and 1% Blankophor P 150. Arkema9466 is formed from an acrylic polymeric dispersion. The dried adhesiveformulation possessed excellent optical clarity.

The indicia 120 utilized at the stations containing flexographic inkcontained multiple lines of a text, an image, and a standard barcode.

The adhesive layer 110 and the overprint layer 130 were optically clearand as such they did not provide any ascetic value or distraction fromthe containers being labeled. Different layouts of the overprint andadhesive layers to maximize material use efficiency were demonstratedwithout impacting the aesthetic value provided by the indicia 120 (seeFIGS. 4A-4D).

The press was run at web speed of 250 feet per minute with forced airovens active after each flexographic station. An electronic vision andregistration system was utilized to register the indicia and coating ateach print station allowing for the coatings and indicia at each stationto be placed on top of the material coated or printed at the previousstation. Multiple rows or lanes of labels were fabricated across thewidth of the web. The carrier film was self-wound at the rewind stationof the press such that the siliconized side was in contact with thepressure sensitive adhesive upon winding.

The carrier film 150 was successfully slit to the width of a singlelabel and rewound without delamination of the thin label from theuncoated side of the PET.

The carrier film web was threaded in a custom fixture that allows theadhesive side of a single label to come into contact with a singlecontainer. The thin labels were successfully transferred from thecarrier film to the container 300 (FIG. 2). Twelve containers weretested, with four in each group. The tested containers 300 includedglass, PET, and PP style bottles.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meanings as commonly understood by one of skill in the artto which the disclosed invention belongs. Publications cited herein andthe materials for which they are cited are specifically incorporated byreference.

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, many equivalents to the specificembodiments of the invention described herein. Such equivalents areintended to be encompassed by the following claims.

We claim:
 1. A label system comprising a thin film label and a carrierfilm, wherein the label comprises an overprint layer, an indicia layer,and an adhesive layer, wherein the indicia layer is located between theoverprint layer and the adhesive layer, and wherein the label has athickness ranging from 0.1 mil to 1.5 mil, preferably the thickness ofthe label ranges from 0.4 to 0.6 mil.
 2. The system of claim 1, whereinthe carrier film comprises a first release layer on a first side,wherein when the system is rolled or stacked, the first release layer isin contact with the adhesive layer.
 3. The system of claim 2, whereinthe carrier film further comprises a second release layer on a secondside.
 4. The system of claim 1, wherein the overprint layer has a hazemeasurement ranging from 0% to 20%, preferably ranging from 0% to 10%,as determined using a haze meter, and an elongation to break of 200% orgreater.
 5. The system of claim 1, wherein the overprint layer is formedfrom one or more precursor materials selected from the group consistingof a solventless UV cured system, water-based or solvent-based solutionpolymers or copolymers, one-part polyurethane system, two-partpolyurethane system, hot-melt polymers or copolymers, and epoxy systems.6. The system of claim 1, wherein the overprint layer is formed from anacrylic-urethane hybrid polymer dispersion.
 7. The system of claim 1,wherein the adhesive layer comprises an adhesive selected from the groupconsisting of a pressure sensitive adhesive, UV cured pressure sensitivecoating, heat activated/thermosetting adhesive, contact activatedadhesive, a fluid activatable adhesive, and two-part thermoset adhesive.8. The system of claim 7, wherein the adhesive is a pressure sensitiveadhesive, and wherein the carrier film comprises a first and a secondrelease liner, wherein the second release liner is in contact with thepressure sensitive adhesive, and wherein the second release linerseparates more easily from the pressure sensitive adhesive than thefirst release liner separates from the overprint layer.
 9. A group ofthin film labels comprising a plurality of thin film labels on a carrierfilm, wherein each thin film label comprises an overprint layer, anindicia layer, and an adhesive layer, wherein the indicia layer islocated between the overprint layer and the adhesive layer, and whereineach of the labels has a thickness ranging from 0.1 mil to 1.5 mill, andwherein each label is discontinuous with the other labels in the group.10. The group of claim 9, wherein the carrier film comprises a firstrelease layer on a first side, wherein when the system is rolled orstacked, the second release liner is in contact with the adhesive layer.11. The group of claim 10, wherein the carrier film further comprises asecond release liner on a second side.
 12. The group of claim 9, whereinthe indicia layer in each of the thin film labels contains a portion ofa complete indicia.
 13. The group of claim 9, wherein when the pluralityof thin film labels is combined, they form a complete indicia.
 14. Thegroup of claim 9, wherein the overprint layer has a haze measurementranging from 0% to 20%, preferably ranging from 0% to 10%, as determinedusing a haze meter, and an elongation to break of 200% or greater. 15.The group of claim 9, wherein the overprint layer is formed from one ormore precursor materials selected from the group consisting of asolventless UV cured system, water-based or solvent-based solutionpolymers or copolymers, one-part polyurethane system, two-partpolyurethane system, hot-melt polymers or copolymers, and curable(epoxy) systems.
 16. The group of claim 9, wherein the overprint layeris formed from an acrylic-urethane hybrid polymer dispersion.
 17. Thegroup of claim 9, wherein the adhesive layer comprises an adhesiveselected from the group consisting of a pressure sensitive adhesive, UVcured pressure sensitive coating, heat activated/thermosetting adhesive,contact activated adhesive, a fluid activatable adhesive, and two-partthermoset adhesive.
 18. The group of claim 17, wherein the adhesive is apressure sensitive adhesive, and wherein the carrier film comprises afirst and a second release liner, wherein the second release liner is incontact with the pressure sensitive adhesive, and wherein the secondrelease liner separates more easily from the pressure sensitive adhesivethan the first release liner separates from the overprint layer.
 19. Athin film label comprising an overprint layer, an indicia layer, and anadhesive layer, wherein the indicia layer is located between theoverprint layer and the adhesive layer, and wherein each of the labelshas a thickness ranging from 0.1 mil to 1.5 mil.
 20. The thin film labelof claim 19, wherein the overprint layer has a haze measurement rangingfrom 0% to 20%, most preferably ranging from 0% to 10%, as determinedusing a haze meter, and an elongation to break of 200% or greater. 21.The thin film label of claim 19, wherein the overprint layer is formedfrom one or more precursor materials selected from the group consistingof a solventless UV cured system, water-based or solvent-based solutionpolymers or copolymers, one-part polyurethane system, two-partpolyurethane system, hot-melt polymers or copolymers, and epoxy.
 22. Thethin film label of claim 19, wherein the overprint layer is formed froman acrylic-urethane hybrid polymer dispersion.
 23. The thin film labelof claim 19, wherein the adhesive layer comprises an adhesive selectedfrom the group consisting of a fluid activatable adhesive, heatactivated/thermosetting adhesive, and two-part thermoset adhesive.
 24. Amethod of making the label system of claim 1, comprising: (a) printingor coating onto the carrier film one or more precursor solutions ordispersions for forming the overprint layer; (b) allowing the coating tocure or dry and form the overprint layer; (c) printing an inkformulation one or more times on the overprint layer to form the indicialayer; (d) coating or printing one or more precursor formulations forforming the adhesive layer on top of the indicia layer and any exposedportion(s) of the overprint layer to form the adhesive layer.
 25. Themethod of claim 24, further comprising rolling the system, wherein theroll comprises a plurality of labels on the carrier film.